Space telegraphy.



PATENTED APR. '7, 1908.

S. CBO'I.'l SPACE TELEGRAPHY, APPLIOATI'ON FILED Nov. 13, 190e.

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srnrns rnrnNr c snwALL cABoT, or BRooKL INE, MAssAcnUsnrrs, AssrGNon'r'o sroNE TELGRAPH AND TELEPHONE COMPANY, OF BOSTON, MASSACHUSETTS, ACORPORATION OF MAINE.

SPACE T ELEGRAPHY.

Specification o Letters Patent.

-1 Patenteaaprn 7, 190s.

Application ijled. November 13, 1906. Serial No. 343,205.

To all whom it may concern:

sonorous circuit is controlled by means of a suitable high potential.key or switch placed in the circuit which connects. the secondarywinding of a high potential transformer wit said sonorous circuit, andin which the sonoreus circuit may be provided Vwith a lurality fserially connected condenser's o large form a part of this specificationI have illus-4 'trated in diagram two arrangements of ap- 'is a sonorouscircuit.

ca acity; y

-n the drawings which accompany and paratus and circuit connectionswhereby the hereinbefore mentioned objects may be carried into effect.

In the drawings* Figure l represents a space telegraph transmittingsystem Y and Fig. 2 represents a combined transmitting and receivingsystem.

A represents a source of vibratory current such for example as analternating current generator, .which is connected through theswitch Nwith the primary 1', of the high potential transformer M, whichpreferably is a closed magnetic circuit transformer. The circuitI S C I1O, which includes the spark gap S, the condensers C C and the primary I1of the oscillation transformer M, The secondary I2 of the transformer Itis connecte to thev sonorous circuit through the intrmediary'of theseries Contact switch or key K, which, as shown, is provided with alight rod e of insulating material carrying the contact members P. Thecontact members P cooperate with the contact members Q supported by theinsulator c. Although not necessary,

Athe contact members P and Q may be immersed in an insulating iiuid suchas the oil G contained in the vessel F. The front and back stops c and bare so adjusted that'when the key K, which is pivoted at d', ismaintained by the spring' c on its front contact c,

the separation of the sev-eral co erating members P and Q at the pointsis not suicient to permit the potential developed at the terminals ofthe secondary I2 to break down the insulation atsaid points and there.by charge the condensers C C. However, when the key is brought againstits back shop t, 'the potential developed at thetermin-als of thesecondary4 of the transformer M is sufficient to rupturethe dielectricseparating the several members P and Q at the points lc and therebylcharge the condensers C C., The

. condensers C C by discharging across the gap S develop electricaloscillations in the sono-l rous circuit and the @I lgy'of Said OSCiuations is translated tothe elevated conductor V by the transformerM, thesecondary of which is included in said elevated conductor, and radiatedin the form of electromagnetic Waves;

It Will be obvious that any number of contact members Pand Q may beemployed, and that the number employed will depend upon the potentialdeveloped at the secondary of the transformer M, while said potential,other things being e ual, will depend upon the length of the spar gap S.By way of example, 1f the length of said gap is one inch and if theterminals thereof are separated by air at ordinaryT pressure, the botertial necessary to cause sparking at said gap will be about 75000 volts.In such case'the separation of the members P and Q at the points 7c maybe one-eighth of an inch and asufficient number of the members P and Qmay be employed to provide eight gaps 7c. There will then be adiscontinuity 1n the intermediate circuit which includes the secondaryof the transformer M and the members Pand Q, of'one inch of dielectricwhich as shown in Fig. 2 may be air, and, inasmuch as a much greaterdifference of potential is required to reak down a'series gap one inchin length and consisting of a plurality of smaller' gaps than isrequired to break down a gap of equal length between two terminals, suchas the spark gap S, no discharge will take place4 across the vseveraljuxta osed members P and Q.` If the stroke of't e key is adjusted toone-thirtysecond of an inch, alarger number of contact members P and Qwould be employed. Preferably the insulatingrod Y' e and themovablecontact members Pare`- made as light as possible so as not tointerfere with rapid signaling, and preferably when -the key is downonits back sltophthemembers P and Q are not brought into co'ritact,

but are separated bysay one-tliirtyesecond vor one-siXty-fourth of aninch at the several Various attempts heretoforey have been' madetoJcontr'ol by means of Morse keys -large l amounts of energy in theprimary .power circuitsfsuchas the 'circuit A N I"of 15- so'l far as"lam 'aware lthese attempts have wireless telegraph transmitting systems,but

not been successfulon account ofv thelarge "amperage developed in 'saidcircuits.. By means of the presentinventioii I provide a meansforcontrolling the current supplied to the sono'rouscircuit in thatpart, of the sysi tern in .which the amperage is small and the principleinvolved therein.

potential correspondingly greater. It will e obvious to those skilled inthe art that many embodiments of my invention may be l devised withoutdeparting from the principlerv thereof as above set forth, and it is tobe understood therefore that the diagrams shownin Figs. land 2 are notto be considered as limitations of my invention, but

merely as conventionalillustrations of the l prefer, as shown in Fig. 2,to operate thekey K. or series contact switch by means of a magnetia2controlled byaii ordinary Morse key K such as used in wire telegraphyThe circuit which includes said magnet and battery B and which is closedat the point 7c mav also include the magnets 1 and r.

ln this case the magnet r2 or its spring c may be so constructed andarranged that the armatures of the magnets 1 and r -will be attractedbefre that of the magnet r2. By depressing the key K the armature t isattracted thereby closing the` contact c and short-circuiting theterminals of the receiving 'system between the points 0 0 across whichthere exists a practically zero differ .ence of potential whenoscillations are created the elevated transmitting conductor sys. tem V.l2 E. The conductor o E is a con ductor having practically ze'roimpedance so that when the' contact 7c is closed the points o o havepractically zero potential to earth. Simultaneously withthe closure oftliecon'- tact f, or before or after said closure, the

4 contact k is o ened by the energization of the magnet 'r' t ierebyopening the circuit of the oscillation detector Y, and finally, afterthe system has thus been put in condition for transmitting the armatureK is attracted and the sonorous circuit is energized. In the ref ceivingsystem, the iiiductance L and the condenser C may be employed foraltering the natural period of the elevated receiving conductor sy'fste'm". M'ffl'a .a transformer, the

vprimaryl, of which is included in the ele- .vatedireceivi'ng conductorsystem and the secondary'lf, of which foriris part ofthe resonantreceiving circuitfC. `The oscillation de tectorY which may be of anysuitabletype and which herein is shown as an anode Z of small areafand acathode z of much larger area immersed in an electrolyte, may beassociated in any suitable manner witlrthe resonant receiving circuit.VT isa telephone and R is a resistance which with the batteryB'constitutes a potentiometer.

Considerable difficulty has heretofore been fexperienced' by wirelesstelegraph engineers in vmaking the condensers of oscillating circuitsstandup tothe high potentials iinpressed upon them. ,Various types ofhigh potential condensers have been devised, but

,on account of the` ionization of the4 dielectric in the immediatevicinity of the edges of the condenser l'plates 4and the resulting brushdischaigesw iich there take place the life ofs'uch condensers is liableto `be shortened. Assuming', by way of eXamplelthat the spark gap S ofthe sonorouscircuit is of such length that 75000 volts. di'erence ofpotential will be developed between the armatures of theoscillating-circuit condenser, the' ionization` of the air `immediatelysurrounding the points of Greatest electrical density willscause a brusht iscliarge which not only kunnecessarily absorbs energy but whichcauses a more or less rapid deterioration of the con'- denserdielectric, .and :this ,is-true even Ialthough( the condenser beimmersed in oil or Y.

otherinsulating fluid. lf instead of using 'one condenser of say 015microfarads capacity, we connectin series with the spark gap S andprimary I, ten large condensers each of .15 microfarads capacity, itWill bev obvious that the resultant ca acity of the oscillation circuitis the same as efore and also that the diHerence of potential .developedat the ter minals of eachv condenser is only 1/10 of what it was before,or 7500 volts. *lf the condensers are each charged to a potential as lowas 7 500 volts, or even to a potential of greater value, no ionizationof the air or other dielectric surrounding the condenser .can

.take place and hence there will be nobrush which may be so thin onaccount of the relatively low. potential developed between the platesthat the desired capacity may be oba normally open intermediate. circuitcontained b v'constitutingeach condenser of two plates o conductingmaterial pasted onthe opposite' sides of a sin le plate of insulating'material such as a. thin plate of glass or a sheet of paraffined paper.Iclaim, f v. 1. In a space' telegraph system, a normally closed powercircuit includ-ing thefprimaiy.

winding of a transformer, a sonorous circuit, a normally openintermediate;V circuit conl necting said sonorous circuit ltothesecondary of said transformer and means operated by a sending key forcontrolling the current flow in said intermediatecircuit- 2. In a spacetelegraph syste,V closed power circuitr-lnclildmg the primary winding ofa transformer, a sonorous, circuit,l

a normally open Aii'iterinediate crC'uitcOnnecting said sonorouscircuit'to the second-. ary of said transformer anda series contact. switch oerated by a sending keyfor coiitrolling t ie current flow in saidintermediate j circuit.

3. In a space telegraph system, a normally closed power circuitincluding the-'primary Winding of a transformer, a sonorous circuit,

necting said sonorous circuitvto the secondary of said transformer,means for controlling said intermediate circuit, a Morse key, and amagnet controlled thereby for operating said means. Y

' 4. In a space telegraph system, a sonorous circuit, a normally closedpower circuit, a

normally open intermediate circuit connecting said sonorous circuit withsaid power 1 circuit, and means for controlling said normally opencircuit, said means comprising a switch having a plurality ofseries-contacts.

5. In a space telegraph system, a normally closed power circuitincluding the primary winding of' a transformer, a sonorous circuit,

a normally open intermediate circuit con-- necting said sonorous circuitto the secondary of said transformer, and means for controlling saidnormally open circuit, said means comprising a switch having a pluralityof series-contacts.

6. In a space telegraph system, a normally closed power circuitincluding the primary.y

winding of a transformer, a sonorous circuit, a normally openintermediate circuit connecting said sonorous circuit tothe secondary ofsaid transformer, and a magneticallytor openeda normally saidintermediate circuit. f f7. In a lspaceftelegraph system, an. elevatedconductor, areceiv'ing system conl i operated series-contact switch forcontrolling 5.5

nected therewith, an oscillation detector Ya'sy vsociated With saidreceiving'sys-temfa transmitting system associated-with Said elevatedconductor, a'sending key and electrorn'agnets controlledby said keyands`o..construjc'te'd and arranged that uponthedepressi'onl-of.

lsaid key Vthe receivingsysteni willlbe shortcircuited., the `circuit ofthe oscillation.d etecenergized and the transmitting..` system l8;Inyaspaceitelegraph system, .an ele- .vated conductor, a receivingsystein' c oI1`-.. l

nectedv therewith,- an oscillation.detectoras!l jv sociated with saidreceiving system, a transfv ;'v

conductor, a sending key'and Aelectroniagnets controlled thereby, meansoperated-by 'oiie of saidI electroinagnets for sliort-circiiiting.

jiiiit'ting system associated-with saidelevated said receiving systemand means operated-by I ling said 'transmitti ngfsystem..` Y y. y 9. In.a space?.telegraph system, van elelanother of: saidelectromagn'ets'ffor controlvated conductor, a,4 receiving system asse-4c iated therewith, an 'oscillation 'detector asfsoci'ated withsaidre'ceiving system', .a trans-- -mitting-system associated with saidelevated conductor, `a sendingkey and three electrom'agnetscontrolledthereby, means operated byvoneof fsaid electromagnets forshort-circuiting said receiving system, means voperated by anotherofsaid electromagnets for opening the circuit 'of' said oscillationdetector, and'means operated by the third electrosecondary winding ofsaid transformer, and a series-contact switch forlcoiitrolling saidintermediate circuit.

In testimony whereof, I have hereunto Isubscribed my name this 12th dayof Nov.,

SEWALL CABOT.:

Witnesses:

E. B. ToMLiNsoN, GEO. K. WooDwoRrH.

